Function for_each_loop_item 

pub(super) fn for_each_loop_item<'gcx>(
    gcx: Gcx<'gcx>,
    func: &'gcx Function<'gcx>,
    follow_calls_outside_loop: bool,
    f: impl FnMut(LoopItem<'gcx>),
)

Calls f for every statement and expression executing inside a loop of func. Internal helpers called from a loop are inlined; with follow_calls_outside_loop, so are helpers called outside one, so that their own loops are reported too.